What's the best FREE Twitter app?

After previously swearing to my friends and family that I would never create a Twitter account, I have finally succumbed to the pressure and created an account.

Since I am new to Twitter, I do not have any interest in paying for a Twitter app for my iPhone, regardless of how inexpensive they might be. However, I would like to get the best FREE Twitter app, just so that I can gauge whether or not I enjoy the service.

Thanks everyone. I downloaded all the recommended apps, and so far I like TweetDeck the most. It may not have all the features of the other apps (like push notifications with Echofon), but the UI is gorgeous and it's easy to use. For now, I think I'll stick with it.

Well, if you're happy with the free, there's not really a need to upgrade as of yet. Just wait until it goes on sale or something. Personally, I NEVER use the free app version. I HATE HATE HATE ads. Just like I HATE HATE HATE commercials on tv.

I like the fact that you can make the tweets different sizes. It has all the features I need, but SimplyTweet has the most features of any that I have used. I think it's the overall best out of all of them, but I can't make the fonts big enough. I have to strain to read the large fonts.

I am debating on which app to use. I have tried TweetDeck,Twitterific,and Echofon. I'm not really sure which one to use. I am looking for something that will tell me when I have a new twit from someone. I know Echofon tells you by the home button, but I kind of want a noise beep that tells me. Any ideas?

Ahh yes the Twitter app debate. I have about 10 different ones and am constantly swapping them back and forth and usually have 3 of them installed at the same time, I can never make up my mind. I go a lot between Twittelator, Tweetie, and Twitterrific.